A three-phase motor located 300 Ft from the power source. The conductors supplying power to the motor is 3/0 AWG copper. The motor full-load current is 60A. What is the voltage drop across the conductors when the motor is in operation?
To calculate the voltage drop across the conductors, we can use the formula:
Voltage Drop = (2 * Length * Current * Resistance) / (1000 * Cross-sectional Area)
Where:
Length = Distance from power source to motor = 300 ft
Current = Full-load current of the motor = 60 A
Resistance = Resistance value per 1000 ft of 3/0 AWG copper wire = 0.0490 Ω (obtained from wire size chart)
Cross-sectional Area = Area of 3/0 AWG copper wire = 0.1678 in² (obtained from wire size chart)
Now, let's calculate the voltage drop:
Voltage Drop = (2 * 300 * 60 * 0.0490) / (1000 * 0.1678)
Voltage Drop = 17.94 V
Therefore, the voltage drop across the conductors when the motor is in operation is approximately 17.94 volts.